cv::text::OCRTesseract Class Reference

OCRTesseract class provides an interface with the tesseract-ocr API (v3.02.02) in C++. More...

#include <opencv2/text/ocr.hpp>

Collaboration diagram for cv::text::OCRTesseract:

Public Member Functions
String	run (InputArray image, InputArray mask, int min_confidence, int component_level=0)
String	run (InputArray image, int min_confidence, int component_level=0)
virtual void	run (Mat &image, Mat &mask, std::string &output_text, std::vector< Rect > *component_rects=NULL, std::vector< std::string > *component_texts=NULL, std::vector< float > *component_confidences=NULL, int component_level=0) CV_OVERRIDE
virtual void	run (Mat &image, std::string &output_text, std::vector< Rect > *component_rects=NULL, std::vector< std::string > *component_texts=NULL, std::vector< float > *component_confidences=NULL, int component_level=0) CV_OVERRIDE
	Recognize text using the tesseract-ocr API.
virtual void	setWhiteList (const String &char_whitelist)=0
Public Member Functions inherited from cv::text::BaseOCR
virtual	~BaseOCR ()

Static Public Member Functions
static Ptr< OCRTesseract >	create (const char *datapath=NULL, const char *language=NULL, const char *char_whitelist=NULL, int oem=OEM_DEFAULT, int psmode=PSM_AUTO)
	Creates an instance of the OCRTesseract class. Initializes Tesseract.

Detailed Description

OCRTesseract class provides an interface with the tesseract-ocr API (v3.02.02) in C++.

Notice that it is compiled only when tesseract-ocr is correctly installed.

Note

• (C++) An example of OCRTesseract recognition combined with scene text detection can be found at the end_to_end_recognition demo: https://github.com/opencv/opencv_contrib/blob/master/modules/text/samples/end_to_end_recognition.cpp
  • (C++) Another example of OCRTesseract recognition combined with scene text detection can be found at the webcam_demo: https://github.com/opencv/opencv_contrib/blob/master/modules/text/samples/webcam_demo.cpp

Member Function Documentation

create()

static Ptr< OCRTesseract > cv::text::OCRTesseract::create ( const char * datapath = NULL, const char * language = NULL, const char * char_whitelist = NULL, int oem = OEM_DEFAULT, int psmode = PSM_AUTO )

static

Python:
	cv.text.OCRTesseract.create(	[, datapath[, language[, char_whitelist[, oem[, psmode]]]]]	) ->	retval
	cv.text.OCRTesseract_create(	[, datapath[, language[, char_whitelist[, oem[, psmode]]]]]	) ->	retval

Creates an instance of the OCRTesseract class. Initializes Tesseract.

Parameters

datapath	the name of the parent directory of tessdata ended with "/", or NULL to use the system's default directory.
language	an ISO 639-3 code or NULL will default to "eng".
char_whitelist	specifies the list of characters used for recognition. NULL defaults to "" (All characters will be used for recognition).
oem	tesseract-ocr offers different OCR Engine Modes (OEM), by default tesseract::OEM_DEFAULT is used. See the tesseract-ocr API documentation for other possible values.
psmode	tesseract-ocr offers different Page Segmentation Modes (PSM) tesseract::PSM_AUTO (fully automatic layout analysis) is used. See the tesseract-ocr API documentation for other possible values.

Note

The char_whitelist default is changed after OpenCV 4.7.0/3.19.0 from "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ" to "".

run() [1/4]

String cv::text::OCRTesseract::run	(	InputArray	image,
		InputArray	mask,
		int	min_confidence,
		int	component_level = 0 )

Python:
	cv.text.OCRTesseract.run(	image, min_confidence[, component_level]	) ->	retval
	cv.text.OCRTesseract.run(	image, mask, min_confidence[, component_level]	) ->	retval

run() [2/4]

String cv::text::OCRTesseract::run	(	InputArray	image,
		int	min_confidence,
		int	component_level = 0 )

Python:
	cv.text.OCRTesseract.run(	image, min_confidence[, component_level]	) ->	retval
	cv.text.OCRTesseract.run(	image, mask, min_confidence[, component_level]	) ->	retval

run() [3/4]

virtual void cv::text::OCRTesseract::run ( Mat & image, Mat & mask, std::string & output_text, std::vector< Rect > * component_rects = NULL, std::vector< std::string > * component_texts = NULL, std::vector< float > * component_confidences = NULL, int component_level = 0 )

virtual

Python:
	cv.text.OCRTesseract.run(	image, min_confidence[, component_level]	) ->	retval
	cv.text.OCRTesseract.run(	image, mask, min_confidence[, component_level]	) ->	retval

Implements cv::text::BaseOCR.

run() [4/4]

virtual void cv::text::OCRTesseract::run ( Mat & image, std::string & output_text, std::vector< Rect > * component_rects = NULL, std::vector< std::string > * component_texts = NULL, std::vector< float > * component_confidences = NULL, int component_level = 0 )

virtual

Python:
	cv.text.OCRTesseract.run(	image, min_confidence[, component_level]	) ->	retval
	cv.text.OCRTesseract.run(	image, mask, min_confidence[, component_level]	) ->	retval

Recognize text using the tesseract-ocr API.

Takes image on input and returns recognized text in the output_text parameter. Optionally provides also the Rects for individual text elements found (e.g. words), and the list of those text elements with their confidence values.

Parameters

image	Input image CV_8UC1 or CV_8UC3
output_text	Output text of the tesseract-ocr.
component_rects	If provided the method will output a list of Rects for the individual text elements found (e.g. words or text lines).
component_texts	If provided the method will output a list of text strings for the recognition of individual text elements found (e.g. words or text lines).
component_confidences	If provided the method will output a list of confidence values for the recognition of individual text elements found (e.g. words or text lines).
component_level	OCR_LEVEL_WORD (by default), or OCR_LEVEL_TEXTLINE.

Implements cv::text::BaseOCR.

setWhiteList()

virtual void cv::text::OCRTesseract::setWhiteList ( const String & char_whitelist )

pure virtual

Python:
	cv.text.OCRTesseract.setWhiteList(	char_whitelist	) ->	None

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The documentation for this class was generated from the following file:

• opencv2/text/ocr.hpp